The present invention relates to a device for the anchorage of an axle at each of its ends, preferably in a pair of fixing lugs or the like, formed with through-holes for the axle, as specified in the pre-characterising part of claim 1.
A known solution according to U.S. Pat. No. 1,493,063 which, however, relates to another application, shows how an axle is divided diagonally at one end so as to form two parts, displaceable in relation to one another. The outer end part is provided with an enlarged axial bore and the inner end part with a tapped bore. A bolt is inserted with clearance through the outer end part so that it interacts with the thread in the inner axle part. When the screw connection is tightened, the outer end part at the dividing line is pressed up to the inner axle part, the parts thereby being wedged together with a surrounding part.
Another known solution according to U.S. Pat. No. 5,538,356 shows an axle which, at its ends, is provided with a tapered section and a central threaded section. The tapered section has alternately tapered and plane surfaces. A uniting collar of alternating internally tapered and plane wedge elements is placed around the tapered section and by means of a nut on the threaded section a movement can be imparted to the tapered section, as a result of which the axle end can be fixed together with a surrounding part.
A disadvantage with the solution according to U.S. Pat. No. 1,493,063 is that the axial bore in the outer end part has to be enlarged in order to permit the movement in a radial direction of the outer end part that is required for it to function. A further disadvantage to this solution is that, if the bolt is screwed up somewhat, so that the wedge connection ceases to act, the axle end can slip out of the surrounding part in an axial direction. This solution also means that the strength at the axle end is adversely affected. Due to the wedge angle required, the solution can only be used where the surrounding part has an elongated fixing aperture and the axle has a relatively small diameter.
Due to the internally tapered wedge elements forming part of the collar, the second solution according to U.S. Pat. No. 5,538,356 has to be tightened up by means of a tightening tool, since mechanical deformation of the said elements is bound to occur if they are forced up on to a section with a different radius of curvature. Furthermore the internally tapered wedge elements will mean that play occurs between the elements of the collar and the axle, since the above-mentioned deformation never permits full contact between the parts, which means that this connection will have to be re-tightened at regular intervals. Tightening also has to be done at both ends of the axle simultaneously, that is to say the axle has to be braced in order to prevent the axle rotating when tightening is carried out. With this solution also, the strength at the axle end is adversely affected. This solution also means a relatively large axial projection beyond a fixing lug, which means that the axle can easily be damaged so that its fixing is broken. Finally it may be noted that this solution probably has very high manufacturing costs.
An object of the present invention is to produce a device of the type initially referred to, which gives the axle ends good strength, which will enable an axle to be anchored at each of its ends in a pair of fixing lugs or the like, formed with through-holes for the axle, the said device allowing easy manual tightening of one side at a time without bracing, and being incapable of accidental removal from the axle when this is placed in the fixing lugs, the said device furthermore being easy and cheap both to manufacture and maintain, and resulting in such extensive free surfaces at the axle ends that necessary text marking can be applied there giving good legibility. The object has been achieved by a device having the characteristics specified in claim 1.
Preferred embodiments of the device moreover have any or some of the characteristics specified in the subordinate claims.
The device according to the invention has various advantages:
Due to the fact that no mechanical deformation of the constituent parts is required during assembly, tightening can be carried out manually without special tightening tools.
Because of the plane slide surface between the axle and the body, full contact is obtained between the body and the axle throughout the tightening process.
The full contact also means greater freedom to choose greater wedge angles, which will facilitate any subsequent dismantling.
The flanges at the segmental-shaped end surfaces of the bodies will function as a physical stop and prevent the axle falling out of the fixing lugs.
In any subsequent dismantling the lip on one side will rest against the fixing lug and be forced to separate from the axle. The lip also provides the facility for using a pull-off tool that grips around this when dismantling.
The lip furthermore means that additional locking devices on the end surfaces or fixing lugs become superfluous, which minimises the axial projection at the sides and reduces the costs.
Other factors which have a positive influence on the cost of the device according to the invention include the fact that the device has few constituent parts and these are simple to manufacture and provides good flexibility.